007, I've asked you before if you have any valid evidence there is a shred of truth to your understanding about the .64 wavelength story and more importantly how does it apply to armature or CB radio. Do you even have a tid bit of history to try and follow up on. The ideas of the 5/8 wave are reported to have been studied in the 1920's and a report was published for the US Broadcast Engineers in 1924. See attached. This is just the 1 page of a 6 page article. I don't make any claims about the attached document, it is available in volume 1 of ARRL Antenna Compendium 1985, by Donald K. Reynolds, K7DBA. It was his recapping of the original study, idea, and possibly some of the results of the original study and was strictly for Broadcast radio.
The science at the time and the study had nothing at all to do with armature radio, in fact the study was regarding ground wave technology which does not even apply above the range of 1-2 megahertz much less 3 megs where armature radio begins and higher.
Ref:
Effect of frequency
As the wavefront of the ground wave travels along the Earth's surface it is attenuated. The degree of attenuation is dependent upon a variety of factors. Frequency of the radio signal is one of the major determining factor as losses rise with increasing frequency. As a result it makes this form of propagation impracticable above the bottom end of the HF portion of the spectrum (3 MHz). Typically a signal at 3.0 MHz will suffer an attenuation that may be in the region of 20 to 60 dB more than one at 0.5 MHz dependent upon a variety of factors in the signal path including the distance. In view of this it can be seen why even high power HF radio broadcast stations may only be audible for a few miles from the transmitting site via the ground wave.
You might be able to find the article on the Internet, but you need to understand some of history regarding this period in order to be able to separate out the wheat from the chaff. I have no proof, but there are foot notes in Reynolds article that may provide more to the story. You will note right off that he does not even mention .64 wavelength and neither did the study.
I have read another article years ago that I've looked for repeatedly and am unable to find. The article is about the Japanese doing a study to discount what the Americans had done in the 1920's concerning Broadcast Radio Antenna development, and thus the account of their ignored and overlooked advantages of the .64 wavelength as being superior to the 5/8 wave.
During this time in history the Japanese were Imperialistic and wanted to rule the world and they started crap with every one that showed to be getting ahead in this world on any score.
If you read Reynold's report and Cebik's recap report on Reynolds report, you will start to get a new view that discounts much of the advantages that have been attributed to the ideas for the 5/8 wave...say nothing about the .64 wave which only existed in the minds of the Japs.
IMO, all of the CBBS on this subject comes from the misunderstandings that are pervasively based on actual facts noted in the original report, but with a slant to the positive that is in error and totally misconstrued. The most glaring thing I find is the iconic charts for gain and height noted below. These two charts are noted on Fig. 3, page 102, of ARRL's Antenna Compendium and they may be right on the money accurate, but the implications in the CB world of what they represent are totally false, because they are misunderstood and do not claim what others have suggested about gain or height. The truth of these two charts are not noted in the images, but in the captions for the images, and without consideration for the words, the ideas are just plain misleading and wrong.
View attachment IMG.pdf